Evidence for Metal−Surface Interactions and Their Role in Stabilizing Well-Defined Immobilized Ru−NHC Alkene Metathesis Catalysts

Abstract : Secondary interactions are demonstrated to direct the stability of well-defined Ru-NHC-based heterogeneous alkene metathesis catalysts. By providing key stabilization of the active sites, higher catalytic performance is achieved. Specifically, they can be described as interactions between the metal center (active site) and the surface functionality of the support, and they have been detected by surface-enhanced H-1-Si-29 NMR spectroscopy of the ligand and P-31 solid-state NMR of the catalyst precursor. They are present only when the metal center is attached to the surface via a flexible linker (a propyl group), which allows the active site to either react with the substrate or relax, reversibly, to the surface, thus providing stability. In contrast, the use of a rigid linker (here mesitylphenyl) leads to a well-defined active site far away from the surface, stabilized only by a phosphine ligand which under reaction conditions leaves probably irreversibly, leading to faster decomposition and deactivation of the catalysts.
Type de document :
Article dans une revue
Journal of the American Chemical Society, American Chemical Society, 2013, 135 (8), pp.3193-3199. 〈10.1021/ja311722k〉
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https://hal.archives-ouvertes.fr/hal-00802998
Contributeur : Johan Alauzun <>
Soumis le : mercredi 20 mars 2013 - 17:58:02
Dernière modification le : jeudi 19 avril 2018 - 14:46:15

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Manorja K Samantaray, Johan Alauzun, David Gajan, Santosh Kavitake, Ahmad Mehdi, et al.. Evidence for Metal−Surface Interactions and Their Role in Stabilizing Well-Defined Immobilized Ru−NHC Alkene Metathesis Catalysts. Journal of the American Chemical Society, American Chemical Society, 2013, 135 (8), pp.3193-3199. 〈10.1021/ja311722k〉. 〈hal-00802998〉

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